Abstract

In oceanography, aluminium is used as a tracer to fingerprintthe location and magnitude of atmospheric dust deposition.Aluminium is particularly suitable as a tracer becauseof its short residence time in surface seawater, its relativelysimple seawater chemistry and the fact that primary input tothe open ocean is by atmospheric deposition. The informationsupplied by surface aluminium concentrations is vitallyimportant to understanding the role that aeolian depositionplays in supplying trace elements to the surface ocean andsubsequent effects on biological processes. The informationis especially important for furthering knowledge of the biogeochemistryof iron. Iron is of particular interest becauseit is an essential element for the growth and metabolism ofall marine organisms despite only being available in extremelylow concentrations (0.1–0.5 nM)1. Iron has been shownto limit phytoplankton growth, which in turn may haveimplications on global climate through drawdown of gasesused in photosynthesis, such as carbon dioxide. An accurateand robust method for determining aluminium is thusvital for continuing studies into atmospheric deposition andsubsequently climate control.